from here down to south of pismo beach. beginning next month 12 days of blasting the water here, every 15 seconds with super loud sound. >> reporter: the power plant could be at risk from undersea earthquake faults. >> the state called for the study and we are committed with working with them. >> reporter: penetrate the ocean floor, echoes reveal faults but it could also hurt marine mammals. >> we will have safe protection zones. >> reporter: there will be only temporary effects on marine life but i obtained this report, there would be significant and unavoidable harm to hundreds of marine mammals. >> we have seen beachings of marine mammals around the world following large noises. >>> they say the state used better and more recent science that are better, less risky methods to explore the faults. >> you can get better, reliable data by going at it another way. >> reporter: puplic comment period is -- public comment period is open for the next three weeks. health and science editor john fowler ktvu channel 2 news. >>> if yo